Abstract: A keyboard includes a plurality of key row holders each supporting a plurality of key elements constituting each of the plurality of key rows, a support shaft placed to be rotatable about an axial center and support the plurality of key row holders arranged to intersect the axial center, an engaging portion formed on a support surface of each of the plurality of key row holders for the support shaft, and an engaged portion formed spirally on a surface of the support shaft in a direction of the axial center so as to be engaged with the engaging portion of each of the plurality of key row holders, the engaged portion causing the plurality of key row holders to shift in the direction of the axial center by an engagement with the engaging portion upon rotation of the support shaft. The keyboard enables easy and accurate key pitch adjustment.